docs: def _post_document_batch(self, batch):
          """
          Send a batch to Cloudsearch endpoint
  
          See: http://docs.aws.amazon.com/cloudsearch/latest/developerguide/submitting-doc-requests.html
          """  # noqa
          target_batch = '/2013-01-01/documents/batch'
          url = self.endpoint_url + target_batch
          return requests.post(url, data=batch, headers={'Content-type': 'application/json'})